EP0668622B1 discloses a solid oxide fuel cell which comprises a plurality of modules. Some of these modules comprise hollow members, which have two parallel flat surfaces upon which the solid oxide fuel cells are arranged. The opposite ends of each module are connected to reactant manifolds by compliant bellow connections.
However, such an arrangement does not provide sufficient thermal and mechanical compliance in the solid oxide fuel cell stack to minimise the mechanical and thermal stresses in the solid oxide fuel cell stack.
EP1419547B1 discloses a solid oxide fuel cell stack, which comprises a plurality of modules. The modules comprise elongate hollow members, the hollow members having a passage for flow of reactant. The modules are arranged so that at least one end of each module is connected to an end of an adjacent module to allow reactant to flow sequentially through the modules in a serpentine type arrangement.
However, the arrangement does not provide sufficient thermal and mechanical compliance to prevent thermal and mechanical stresses building up near the elongate hollow members. Furthermore, inspecting the modules for joint leakage, geometrical accuracy and reactant pressure drop across the module prior to installation in the stack is difficult.